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859 Uppsatser om Genetic parameters - Sida 4 av 58

Självmord : en forskningsöversikt

Suicide is the ultimate outcome of mental illness and is a big and serious problem in society. About 1500 persons commit every year suicide in Sweden and many more engage in suicidal behaviour. This review aims at, from research studies from the 21th century, find out the knowledge of riskfactors regarding the risk for committing suicide among adolescents. The research questions are: What does research say, from a psychobiological perspective, about riskfactors among adolescents regarding the risk for suicidal behaviour? How much does genetic factors have an effect on the risk for suicidal behaviour among adolescents? and : What is the importance of environmental factors such as family connections, friends and school environment concerning suicidal thoughts among adolescents?The method that is used in order to answer these questions is a researchreview including ten research-studies.

Modellering och reglering av mjölkningsrobot

In this master thesis a robot arm belonging to an automatic milking machine from DeLaval is investigated. The robot arm is controlled by a pneumatic cylinder and a valve. The goal of the master thesis is to investigate instability problems and to find out if it is possible to solve them by using gain scheduling. Gain scheduling is a type of controller where the parameters of the controller are changed during operation, for example depending on the working point. First a nonlinear mathematical model of the system was made.

Pelletering av tallspån : grundläggande studier

Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity. Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures.

Phenotyping of Bali cattle and interviewing farmers in Indonesia - a minor field study

Among the Indigenous cattle breeds in Indonesia, the Bali cattle is the most preferred by small farmers. The Bali cattle is a beef breed, and is considered to have several advantageous characteristics and to be well adapted to the country?s harsh environmental tropical conditions with drought and rain. The main aim of this project was to phenotype of Bali cattle from different locations in order to identify and document diversity within the Bali cattle breed based on their observable characteristics, to compare cattle from different areas and production systems to see the effect of management on phenotype. In this study, 107 cows and bulls of the breed Bali cattle, from Kalimantan, Sumatra, Lombok and Bali were phenotyped.

Fertility before and after installation of Herd Navigator?

The fertility of dairy cows is of great importance in order to maintain high production. The decline in fertility of dairy cows the latest decades can have several explanations. The large emphasis on high yielding cows and the negative genetic correlation between milk production and fertility traits could be one of the main factors for impaired fertility. To find heats and inseminate the cow at the right time is crucial to receive high conception rate. Delaval has, in corporation with FOSS, developed Herd Navigator which is a management program that measure four biological parameters in the milk; progesterone, betahydroxybutyrate, lactate dehydrogenase and urea.

Implementering av en PSS i Trängslets kraftstation

The purpose of this master thesis is to implement and validate a Power System Stabilizer (PSS) to a generator at Trängslet hydropower station in Dalarna, Sweden. Problems with local rotor oscillations can occur at the hydropower station when power is transferred on a new power line (130 kV) from Northern to Southern part of Dalarna. To ensure good operation properties on this power line Fortum Generation AB and Fortum Distribution AB wants to activate a PSS on a generator.There have been investigations in which situations and what equipment that contributes to rotor oscillations. When this is known the PSS is tuned to damp these oscillations by choosing a good set of parameters. The most important parameters for good performance are to choose amount of gain and phase compensation.

Processutveckling av borstgradning

During the milling of Sandvik Coromant?s world leading Drill with replaceable inserts,the CoroDrill880©, burrs appear around the milled surfaces. The burrs are removedusing different methods, one of which is deburring with special brushing machines thatare integrated into milling cells. The machines of the type Sinjet, use a Siemensguidance system. The deburring results are not satisfying and manual deburring isrequired afterwards.

Nätnyttomodellen och dess inverkan på ett distributionsnät - En studie i samarbete med Härryda Energi AB

This report is intended to give an insight in the Network Performance Assessment Modeland the parameters that is needed in the making of a fictitious grid that represents anoptimal grid. A main goal is to investigate how the construction of a real grid iscompared to the fictitious.One of the key parameters is how redundancy is treated in the model and to find theoptimal amount of redundancy versus the costs. Further is the dimensioning of the grid ofinterest. The fictitious grid is based on energy whereas the real grid often is based onsubscribed power and these two principles are compared and analyzed.The difference in the outcome of the model result due to variations in input data of themodel is also discussed in the report..

Genomisk selektion och uppbyggnaden av avelsprogram hos mjölkkor

During the last decade a new technique in animal breeding has developed called genomic selection. It is based on estimations of the effect from genetic markers on traits that are calculated in a reference population. By genotyping individuals, genomic breeding values can then be estimated without phenotypic observations. The aim of this essay is to investigate the response of genomic selection on breeding schemes for dairy cattle. The accuracy of the genomic breeding values is affected by the proportion of observations included in the validation set and how often the equation for estimating breeding values is reevaluated.

SAMMANS?TTNING AV MAKROALGER I SVENSKA ?LGR?S?NGAR eDNA sp?rning och klimatf?r?ndringar

The aim of my bachelor?s thesis is to investigate, through a literature review, changes in the distribution of filamentous algae as well as the general species composition of macroalgae and diatoms in Swedish eelgrass meadows. I have also studied the possibility of tracking these algae and diatoms in eelgrass meadows using eDNA methodology. The focus has been on linking these changes to climate change factors such as eutrophication, temperature increase, and anthropogenic emissions, and how these affect the health of eelgrass meadows and their ecosystem services, such as a carbon sink and biodiversity support. The results show that filamentous algae have increased markedly in coverage in Swedish coastal areas between 1980 and 2021, especially in sheltered bays, indicating that altered environmental conditions favor these fast-growing species. Genetic tracking using eDNA demonstrated that there are functional primers for many species, particularly among brown algae and red algae, whereas green algae require more specific primers due to greater genetic variation.

Genetisk analys av data från fölbesiktning och jämförelse med resultat vid treårstest :

More than 1000 Swedish Warmblood foals are shown every year at foal inspections which are arranged around the country. Six traits are evaluated at these inspections: type, head-neck-body, correctness of legs, walk, trot and canter. No previous genetic studies have been done on the data from these evaluations. The purpose of this study was to do genetic analyses of the traits which are evaluated at foal inspections. The purpose was also to see if there are any correlations between the results of the foal inspections and the results from the tests of three-year-old horses.

Elitskon : An objective kinematic evaluation

Elitskon? is a new type of horseshoe for trotters. It is supposed to give the horse a trot that mimics the movement pattern of a horse trotting unshod. Many horses show a better trot unshod but this can only be used to a limited extent due to the great wear and tear of the hoof. The objective of this study was to evaluate whether the qualities of Elitskon? are similar to the unshod horse or the traditional aluminium horseshoe.

The genetic background of oxytocin and its importance for maternal behaviour of sows

Oxytocin is today widely spoken of as a "feel good" hormone. Recent research has increased interest in the hormone and its role in social and sexual interactions, as well as its importance for complex behavioral patterns. There is evidence that oxytocin is released during physical contact and is said to suppress anxiety and stress. In animals and humans, oxytocin, which is a neuropeptide and likewise a hormone, is necessary for parturition and lactation. Synthesis of oxytocin occurs in brain neurons and in specific organs involved in reproduction.

Naturhänsyn vid föryngringsavverkningar : En jämförelse mellan certifierade och o-certifierade hyggen

A growing number of Swedish forest owners are choosing to certify their forestry. However, there appears to be a lack of field surveys which describe differences between certified and non-certified forests concerning the degree of completed environmental considerations. In order to know to what extent certified forests contribute towards improved environmental consideration, we need studies on how large the difference is in relation to non-certified forests.Differences between certified and non-certified forest clearings were quantified through an inventory of the number of retention trees, dead trees and snags. The result showed that the retained number of the investigated parameters varied greatly between individual clearings, regardless of certification status. However, the results suggested that the certified clearings had an average higher incidence ofthe investigated parameters.

Noggrannhet vid målinmätning : Analys av ett eldledningsinstrument med förbättringsförslag

This Master Thesis has been conducted as an assignment of the Swedish Defence MaterialAdministration and the Swedish Armed Forces and aims to examine the Target Location Error(TLE) of a Forward Observer System. The targeting accuracy of the system is vital if the systemis to be used as a sensor for precision munitions. The analyzed system, EOI (FOI 2000), wasdelivered to the Swedish Armed Forces in 2007. The targeting sequence starts with deciding theposition of the system with a GPS-receiver, continues with methods where the north direction issettled and ends by measuring the distance, direction and elevation to the target. When allparameters have been measured the system calculates the position of the target.

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